Breeding for Organic Field Crops in Canada
An overview of research in the Organic Science Cluster program Published March 2020
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rganic field crop farmers are constantly searching for ways to improve their crop yield. Crop genetics have a significant influence on how plants grow, yield, and respond to stress as well as their quality attributes. Researchers and breeders are trying to understand if there is an advantage to breeding crops specifically for organic production. They also have recognized that the needs and interests of organic farmers may differ from those of conventional farmers. Over the last 10 years, researchers and breeders involved with the three Organic Science Clusters have been exploring approaches to breeding cultivars suitable for organic management. They have looked at the costs and rewards in organic breeding and the impact these cultivars may potentially have on the industry. Specifically, they have been working toward addressing three questions: 1. Can cultivars that are bred under conventional management with high inputs thrive under organic production? 2. Is it worthwhile to be breeding cultivars under organic conditions for organic farmers? 3. Is it useful to have organic farmers participating in the breeding process?
DEFINITION
Classical or traditional breeding is breeding that relies on phenotypic selection, field based testing and statistical methods for developing varieties/breeds or identifying superior individuals from a population. The steps to conduct breeding include: generation of genetic variability in populations for traits of interest through controlled crossing (or starting with genetically diverse populations), phenotypic selection among genetically variable individuals for traits of interest, and stabilization of selected lines to form a unique and recognizable cultivar/breed. Classical breeding does not exclude the use of genetic or genomic information to more accurately assess phenotypes, however the emphasis must be on whole organism selection.
CHALLENGES IN ORGANIC BREEDING Our natural landscape is highly variable in its soil, climate and pest pressure across regions and within fields. Natural ecosystems have a diverse range of plants that are genetically adapted to occupying specific environmental niches which give them a competitive advantage over other plants. In agricultural cropping however, a single cultivar of a single species of crop is planted across the entire landscape. As crop breeding and seed production evolved through the 20th century, farmers typically chose the best cultivars from performance trials in their region. However, these cultivars are largely developed and tested under conditions of high fertility, low weed pressure, and an average soil condition. While the cultivars are adapted to the regional climate, fertilizers and pesticides are used to support the crop across a wide range of niches that may exist in a field or even within a region. Field crops growing under organic management more typically have lower fertility (or different timing of nutrient availability), higher weed competition which is managed through cultivation, and few options for controlling insects or diseases. Organic farmers have had to rely on cultivars that have been bred under non-organic conditions. This means that although their field crops are produced and harvested under organic conditions, the cultivars used were not bred under organic conditions. Cultivars bred under conditions supported by synthetic fertilizers and pesticides may not thrive under organic conditions where these practices are prohibited.
DID YOU KNOW? It takes approximately 10 growing seasons and $1 million to produce a new cultivar under classical/traditional breeding approaches.
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